Electron discharge device



Sept. 1, 1936. M K g'gm 2352 61 ELECTRON DISCHARGE DEVICE Filed Feb. 14, 1933 5 Sheets--Sheet l JNVEN TOR. WWW Z! 5042572747 A TTORNEYgZ.

' 1 (1 I I r fiwo M. K eomsnzm fi fi ELECTRON DISCHARGE DEVICE Filed Feb. 14, 1933 5 Sheets-Sheet 2 ATTORNEY Sept. 1, 1936. M. K. GOLDSTEIN 2,052,617

ELECTRON DI SCHARGE DEVICE Filed Feb. 14, 1933 5 Sheets-Sheet 3 I Mpaz :Zqjf MVENTOR fiyl mix M41 airway/72w MM ATTORNEY p 9 193a M. K. eow mm ELECTRON DISCHARGE DEVICE 5 Sheeis-Sheet 4 k F (v p L 1936- M. K. sows-rem 2,052,617

ELECTRON DISCHARGE DEVICE Filed Feb. 14, 1933 5 Sheets-Sheet 5 I IN-V EN TOR.

A'TTORNEYKY Patented Sept. 1, 1936 UNITED STATES PATENT OFFICE 15 Claims.

My invention relates to electron discharge devices and radio systems for the transformation and modification of direct current energy or electrical energy at both audio and radio frequencies. More particularly my invention pertains to shielding construction for electron discharge devices of multi-plex type, and associated circuits.

Multi-plex tubes of the prior art, as known by me, have been limited in their application and usefulness by reason of the fact that the attempt to combine the function of more than one electron discharge device into a single device has introduced new and unforseen complications in the operation and construction thereof. These complications have arisen due to the fact that the electrodes of one group have been necessarily located within the sphere of influence of the electrodes of another group, thus permitting each group of electrodes to exert undesirable influence upon the electronic action taking place among the electrodes of another group. These undesirable conditions invariably resulted in a distorted output. Spacing the groups of electrodes so that they no longer occupy a position within the sphere of influence of other groups might serve to substantially reduce these disturbances. Practical considerations however, would not favor this practice, as it would not only result in unduly enlarged tubes, but would also result in a requirement of separate sources of electron emission for each group and in addition thereto would increase the tendency for development of dissimilarity, in characteristics of corresponding groups of electrodes. The multiplication of electrode groups would also be thereby inhibited.

It is an object of my invention to provide an electron discharge device of multi-plex type which shall be capable of performing the functions of a plurality of discharge devices without the interelectrode group coupling effects characteristic of multi-plex tubes referred to above.

Another object of my invention is to produce an electron discharge device of the multi-plex type wherein the electrode groups may be compactly assembled without inter-action therebetween.

Another object of my invention is to produce an electron discharge device of the multi-plex type so designed as to readily permit of the multiplication of electrode groups whereby to obtain the functions of a number of electron discharge devices of the single electrode group type.

Another object of my invention is to produce an electron discharge device of the multi-plex type which is compact and rigid in construction.

Another object of my invention is to produce an electron discharge device of the multi-plex type capable of many and varied uses.

Another object of my invention is to produce an electron discharge device of the multi-plex type so constructed as to permit each group of electrodes to perform the function of a diiferent tube in radio circuits or circuits of similar type without undesirably affecting the functioning of other electrode groups in the same device,

Another object of my invention is to provide an electron discharge of the multi-plex type having its grid terminals so positioned as to provide a minimum of capacity between the leads thereto.

Another object of my invention is to produce an electron discharge device of the multi-plex type having a high amplification factor and wherein the elements which contribute toward creating this high amplification factor also serve to mechanically contribute toward rigidifying the electrode assemblage of the device.

An additional object of my invention is to provide a novel electron discharge device of the multi-plex type and suitable circuits associated therewith.

Another object of my invention is to provide an electron discharge device of the multi-plex type capable of performing the functions of the tubes of a radio circuit but requiring less connections and otherwise resulting in a simplified circuit arrangement.

A further object of my invention is to provide an electron discharge device embodying a plurality of multi-plex sections.

Additional objects of my invention reside in a electron discharge of the multi-plex type having certain novelties of construction and function which will be more clearly pointed out in the following description and claims taken in connection with the accompanying drawings Wherein:

Fig. 1 is a view in perspective of an electron discharge device of a duplex type partly broken away to expose the electrode structure within.

Fig. 2 is a view in cross section of Fig. 1 taken along the line AA.

Fig. 3 is a view of a sealing washer employed in the construction of the device of Fig. 1 but not shown in Fig. 1.

Fig. 4 is a view illustrating the grid terminal layout for the device of Fig. 1.

Fig. 5 is a schematic diagram of the elements of the device of Fig. 1 showing the connection of said elements in circuit.

Figs. 6-17 inclusive are diagrams illustrating the manner of connecting the device of Fig. 1 in a number of circuits of various types.

Fig. 18 is a view similar to that of Fig. 1 except that it discloses the electrode arrangement of a quadra-plex tube instead of one of the duplex type.

Fig. 19 is a view of a shielding and spacing ele ment employed in the construction of the device Of Fig. 18.

Fig. 20 is a view of the device of Fig. 18 illustrating the layout of grid terminals.

Fig. 21 is a view in perspective partially broken away showing one group of electrodes and the shielding housing therefor.

Fig. 22 is a view in cross-section illustrating electrode groups of different dimensions.

Fig. 23 is a view in perspective partly broken away, illustrating the electrode structure and shielding means for a discharge device according to my invention embodying a plurality of multiplex devices in the same envelope. I

Fig. 24 is a view illustrating a construction of a multiple multi-plex device which my inven tion may be embodied in.

Refer-ringto Fig. 1-41 have disclosed therein an electron discharge device comprising a housing l provided at its lower end with a base portion 3 of any suitable insulating material. The housing may be provided with the customary press, not shown, for supporting the internal elements of the device. C'o-axially with the lon-v gitudinal axis of the housing is mounted a source of electrons preferably a cathode of the indirectly heated type. A cathode of this type comprises a heater element 5 mounted within a spool "l of refractory material. The outer surface of which iscoated with a material possessing rich electron emissivity characteristics. I

Surrounding the cathode and concentric therewith, are arranged a plurality of groups of similar electrodes, each group comprising a control grid 9 and an anode l l. Ascreen grid l3 between the grid and the anode of each group when con 7 nected to a source of positive potential will serve to remove the space charge normally tending to develope around the cathode, and at the same time reduce the internal grid-anode capacity, thus accelerating the flow of electrons, and increasing. the amplification factor of each group of electrodes, and at the same time forestalling the possibility of said groups breaking into undesirable oscillation.

In combination. with the electrodes as just described, I provide an additional grid element l5 for each group and position this grid between the "screen grid [3 and that face of the anode exposed to the stream of electrons from the cathode. This additional grid or suppressor grid, as it is sometimes termed, when at zero potential with respect to the' cathode or at a negative potential with respect thereto, will exhibit the property of repellinglsecondary electrons knocked out from the surfaceof anode during bombardment of .the anode by the primary electrons arriving from the cathode, thus permitting the screen grid electrode to more efiiciently function as an acceleratingelectrode. The suppressor grid furthermore will aid "the screen grid in its function of reducing the control grid-anode capacity in that it itself constitutes an electrostatic screen between the controlgrid and the anode. The fact that the screen grid is maintained at a positive potential renders it possible for the suppressor grid to function as an electrostatic screen withouta detrimentalzefiect uponthe flow of primary electrons to the anode. The supressor grid should preferably extend for a short distance above and below the anode, and may be electrically and physically connected to an outer grid I! extending over the outside surface of the anode.

Between the two groups of electrodes, are located elements E9 of conductive material. These may take the form of metallic strips of rectan gular shape positioned radially with regard to the cathode, the strips being of such width as to ex: tend from the region closely adjacent to the cathode to the outer screen element H to which it may be crimped, welded or otherwise secured. These'elements also should extend for a short distance above and below the upper and lower edges of the anodes.

Washers 29 of metallic material are mounted on the radially positioned elements it! and united thereto by welding, crimping or otherwise. In Fig. 2, I have illustrated a washer of this type for use in the upper portion of the tube of Fig. 1. It is provided with slotted openings 23 adapted to receive the extended portions of the radially positioned elements IQ for attachment thereto. Additional openings 25 are provided through which to draw leads from the control grids 9 to terminals mounted 2'! on theupper walls of the tube I at points diametrically opposite to each other whereby to reduce inter-lead capacity to a minimum.

The washer for mounting on the lower edges of the radially disposed elements is similar to that of Fig. 3 except that the openings for withdrawing leads will diifer in number and position to suit the requirements of the remaining electrodes in the tube, the leads to these electrodes being preferably withdrawn throughthe base to terminate in prongs molded therein in the customary manner. In lieu of employing the lower Washer, a beneficial shielding effect can be obtained by extending the elements l9, suppressor grids and outer grids below the lower edge of the anodes, such extensions, particularly of the radial elements, also inherently functioning to provide effective shielding between the electrode leads.

The radially disposed elements 59 in combination with the upper metallic washer 2i, and the outer grids ll constitute chambers, each chamberhousing the control grid and anode of a group and substantially enclosing the same, thus both mechanically and electrostatically isolating the so-called. active electrodes of each group, namely, the grid and anode electrodes from the corresponding elements of the other groups. The lower washer when used will serve to render more effective, the shielding function of the housings.

According to customary practice, the screen grids of the majority, if not all of the tubes of a circuit may be maintained at one and the same positive potential and similarly in circuits employing suppressor grids, the suppressor grids may also all be maintained at a common potential with respect to the cathode, which potential may be either zero potential or a slightly nega tive one. Thus in the device as described by me, I contemplate uniting the screen grids and in like manner the suppressor grid elements of all the group-s. The screen grids can be so united by merely providing a continuous screen between the grid electrodes and suppressor grid elements.

Suitable slots 29 may be cut in the wing elecing the same at their vertical edges to the radially disposed elements. This connection to the radially disposed elements is made possible by reason of the fact that these elements can be maintained at the same operating potential as the suppressor grids in the majority of circuits. The outer grids may also be united into a single element by initially providing a continuous sleeve of conductive material about the whole assemblage and uniting it to the suppressor grids and wing elements.

With the electrode elements united or combined as described above, it should be apparent that the suppressor grids and outer grids individually or combined will brace the radially disposed elements and the electrode structure of the tube will otherwise have been made extremely rigid, leading toward a more stable and. efiicient operation of the same.

Another advantage arising out of the construction of the above device resides in the feature that the capacity to ground or any other fixed reference point, of the corresponding elements of the various electrode groups will be of the same magnitude and this value will remain fixed. In the design and operation of the radio apparatus, this condition is one highly to be desired as it results in a system of great stability.

In Fig. I have illustrated the relative positions and connections of the electrodes in a device of the du-plex type constructed according to my invention. The heater 5 is supplied with unrectified alternating current through the medium of a transformer not shown connected to a suitable supply source. The cathode l is customarily connected to an electrical mid-point of the transformer secondary, either by a direct connection thereto or through suitable impedances bridging the transformer secondary. The suppressor grids IS, the outer grids l1 and radially disposed elements iii are all connected together as a unit in like manner, the screen grids l3 are connected together as a unit.

In Figs. 6-17 incl., I have disclosed circuits designed for operation with my improved device.

Fig. 6 depicts a circuit for obtaining two separatestages of triple grid amplification. In the system as shown, the suppressor grids 15 the outer grids ll and radial extending elements ii! are tied together and placed at a negative potential, the screen grids l3 also being connected together and the proper positive potential applied thereto. The input signal is impressed upon one of the two control grids 9 of the device by means of a transformer 3| and appears in amplified form in the circuit of its associated anode. Coupled to this anode circuit by means of a transformer 33 is the grid circuit of the other electrode group. Thus the amplified signal is impressed upon the grid of this group whereby it is again amplified, to appear across the transformer 35 in the output or anode circuit of this electrode group.

The circuit of Fig. '7 illustrates the circuit equivalent of two separate stages of triode amplification. In this circuit, the suppressor grid l5 of each electrode group together with the outer grids l! is employed as the control grid, the regular control grid 9 being connected to the radi ally disposed elements l9 to the negative end of a variable potential supply source 31. The screen grid elements [3 in this circuit, while they will function to accelerate the electron fiow to increase the amplification factor of the electrode groups, are not in position to reduce the grid-: plate capacity. Thus eachelectrode group will function as a triode having a high amplification factor. The signal itinerary will otherwise be similar to that of the circuit of Fig. 6.

In Fig. 8 the duplex device of my invention is shown connected in a circuit for push-pull triode operation. In this circuit as in that of Fig. 7, the regular control grids 9 are electrically connected to the radially disposed elements 19 and maintained at a low negative or zero potential. The suppressor grids l5 and outer grids I! are utilized as the control grids. The circuit is otherwise similar to a standard push-pull circuit.

The circuit of Fig. 9 is somewhat similar to that of Fig. 8, except that the input signals are applied to the regular control grids 9 and the suppressor grids i5 and outer grids I! are connected to the radially disposed elements [9. When so connected, the discharge device of my invention is connected for push-pull pentode operation, that is, it is equivalent to two pentode tubes connected for push-pull operation.

Figs. 10 and 11 disclose circuit connections whereby my device may be arranged for parallel operation as pentodes and triodes respectively. For pentode operation, both control grids 9 are connected in parallel to the same end of the secondary winding of the signal input transformer 3E and the anodes H are similarly connected to one end of the primary of the output transformer 45. The suppressor grids l5, the outer grids l1 and radially disposed elements I9 are connected together at a slightly negative potential. Suitable control grid and screen grid potentials are supplied to these elements.

The circuit of Fig. 11 differs from that of Fig. 10, in that the suppressor grids 65 are employed as the control grids and the regular control grids 9 are connected to the radially disposed elements Hi. This shift in connection changes the pentode parallel circuit of Fig. 10 to the triode parallel circuit of Fig. 11.

Fig. 12 shows the du-plex device of my invention connected up in another manner for class- B operation. In this system as illustrated, the control grid and screen grid of each electrode group are electrically connected together and the signal impulses are impressed upon both of them as one. Thus the use of the two grids 9 and I3 for a control grid and the use of the suppressor 5 at an appropriate positive or negative poten tial can be effective in cutting the plate current to or close to cut off value. Thus no plate current flows in one group when the other plate circuit is drawing current. This is due to the fact that only a positive half cycle of signal energy is capable of causing a plate current to flow. The biasing or grouping of the appropriate electrodes is the distinguishing characteristic of amplifiers the class B type. As in the circuit of Fig. 9, the outer grids and the radially disposed elements are electrically connected to the suppressor grids.

13 describes a push-pull detector of the power or linear detection type. This is essentially similar to Fig. 9 except that the control grids are biased to such a degree that little plate current flows. This push pull detec ion circuit permits handling of large input signals and does not allow the annoying radio frequency component of the input signal to appear in the plate circuit. Thus no radio frequency filtering of the plate output is necessary, and due to the balanc ing output arrangement, direct current saturation of the output transformer core is avoided. A comparatively high negative bias for the control grids will be necessary. This is the distinguishing characteristic of detectors of the power or linear detection type.

Fig. 14 represents a du-plex tube of my construction employed in a circuit as a parallel operated detector. The circuit is similar to that of Fig. 10 except that the control grids are biased for operation on the lower bend of the plate current characteristic curve. Parallel operation gives twice the conductance for a given input signal potential thereby resulting in twice the power output.

The arrangement of Fig. 15 discloses the control grids 9 of my device connected in push-pull, whereas the anode electrodes H are connected for parallel operation. The suppressor or electrodes IS the outer grids I? and the radially disposed elements l9 are all tied in to a negative terminal of a source of bias potential. This circuit possesses the advantage of no radio frequency filtering being necessary in the output circuit, which for a single tube detector would appear in the next audio tube circuit due to the distributed capacity of the transformer, even though the output plates may be connected in parallel.

Fig. 16 depicts a novel circuit involving my device as a generator of oscillations. In oscillators of the prior art, it is a Well known characteristic thereof, that the frequency, unless crystal controlled, will shift to an undesirable degree in response to variations of electrode potentials. This is attributed to the fact that the oscillators of the prior art comprise unsymmetrical circuits. The circuit disclosed by me in the above figure constitutes a symmetrical layout. The frequency determining circuit comprising the coil ill and shunting condenser i3 is connected between the control grids e. The anode circuits are symmetrically coupled to the frequency determining circuit by means of output inductors 45 and an output circuit may be coupled to the anode circuit inductors. The suppressor grids l and the radially disposed elements H] are maintained at a slightly negative potential. By reason of the symmetrical arrangement of the electrodes in this circuit, any variation in potentials occurring in the supply sources will affect both sides of the circuit in equal and opposite fashion, thus counteracting the frequency shifting effect of the potential changes on each electrode. Moreover the symmetrical layout will not permit any even harmonics to be present in the output circuit. This is of great importance in superheterodyne receivers where the second harmonic causes strong signals to appear on more than one point on the receiver dial. Thus the advantages of frequency stability and reduction of repeat points of strong signals may easily outweight the added circuit necessary to effect this.

In Fig. 17 I have embodied the same frequency stabilizing feature in an oscillator of the dynatron type. The characteristic feature of a dynatron oscillator is the fact that a higher positive potential is impressed on one of the grid electrodes than on the anode. To fulfill this condition in the circuit illustrated, the positive potential on the screen grids l3 is made of a higher value than that impressed on the anodes l i. The suppressor grids, the outer grids, the control grids and the radial disposed elements are all electrically connected together and grounded through a low negative potential. An output circuit may be provided and this can be coupled to the anode circuit as'shown. By reason of the symmetrical arrangement of elements, frequency shifts normally attributed to changes in electrode potentials will be avoided. As in the circuit of Fig. 16, even harmonics will be obliterated with the same advantages discussed above.

In discussing the circuits of Figs. 6-17 incl., it should be 'noted that certain of these circuits call for the radially disposed or wing elements to be connected to the suppressor grids whereas others require that the wing elements be connected to the control grids and in some cases to both the control grids and the suppressor grids. And in one of the circuits, namely, that of Fig. 12 the screen grids are connected to the control grids. Thus to provide a tube capable of fulfilling the requirements of all these circuits as well as innumerable others, necessitates a device of extreme flexibility. This characteristic is inherently embodied in my device if in lieu of joining electrodes within the tube, individual leads from all the electrodes be brought out from the device to external terminals whereby the electrodes may be connected up into any desirable arrangement.

This individual terminal construction is particularly desirable in circuits of the type involving push-pull or parallel operation of electrode groups wherein the screen grids may be separately connected to the source of positive potential. Thus, should it become necessary to obtain an accurate and fine distribution of load between the electrode groups, it can be accomplished by a slight shift in the potential on one or the other of the screen grids.

In general, however, Where the device is to be employed in circuits requiring a positive potential on the screen grids and a zero or slightly negative potential on the suppressor grids, the outer grids and wing electrodes, the electrodes may be united within the tube in the manner described above. This will bear an advantage over the individual terminal construction in that the number of external connections necessary will be appreciably reduced. Thus in the du-plex device described by me, the number of such external connections will be reduced from thirteen terminals to eight. Yet this device with only eight terminals is capable of push-pull, parallel, cascaded triple grid amplification and other modes of operation.

So far, my discussion has been limited more or less to my invention as embodied in a du-plex device. My invention is not limited, however, to a two section tube. In fact, my invention finds its greatest field of use preferably in devices having a large number of sections. This is permissible by reason of the basic construction of my invention whereby each electrode group is substantially enclosed by shielding structure. In Fig. 18, as an example, I have disclosed my invention as embodied in a four section or quadraplex device and in Fig. 21, I have disclosed one of these sections by itself. The sections are similar to those of Fig. 1, except that they do not cover the same angular displacement. As in the device of Fig. 1, individual terminals may be provided for each electrode or the electrodes may be joined internally of the tube in the manner discussed above in connection with the device of Fig. 1, in which case the screen grids will preferably be constituted by a single screen surrounding the control grid electrodes; and the wing elements, the suppressor grids and outer grids will also be united. The shielding washers, the upper one of which is disclosed in Fig. 19 will be provided with four radial slits 23 to receivethe wing elements [9 when positioned on the electrode assemblage. Openings 25 are formed in the shielding washer to permit of the passage of grid leads to the grid terminals 21. These terminals may be spaced equally about the upper portion of the tube as illustrated in Fig. 20 which portion may be of dome shape. The equal distribution of terminals in this manner reduces the inter-grid lead capacity to a minimum.

In devices constructed according to my invention having a large number of electrode groups, the shielding structure renders it possible to utilize certain groups as radio frequency amplifiers in cascade, push-pull or parallel operation, certain of the groups as detectors, other as oscillators or audio frequency amplifiers in any desired arrangement. In fact, it is conceivable that a single multi-plex device might be employed to replace all the tubes of a modern receiver.

The various embodiments of my invention as described above, all disclose the electrode groups in any one device as being of equal size and similar characteristics. It may be preferable, in the majority of uses to which my invention is adapted, to construct the groups of varying sizes and characteristics to conform to the power requirements and operating characteristics of the particular portion of a circuit or system in which each group is to be connected. Thus for radio frequency amplifiers, where the power load is small, the sections may be constructed small. This will leave more space for the audio frequency amplifiers or the like which handle a comparatively large amount of power and thereby should be of larger construction.

As a further modification of the devices such as described in Fig. 1 and Fig. 18, I contemplate constructing a device having a plurality of multiplex sections in the same envelope.

In Figure 23, I have illustrated an embodiment of my invention incorporating both of these features, namely, a plurality of multi-plex sections having electrode groups of unequal dimensions and characteristics. This modification I term a multiple multi-plex device in that, as the name implies, it comprises a plurality of multi-plex devices within the same envelope. These may be mounted one above the other, utilizing a single cathode 1 extending the length of the structure for supplying the electrons to all the electrode groups of the multi-plex sections. The electrode groups may cover any angular displacement sufficient for the efficient operation of the same, as clearly illustrated for example in Figure 22, and the number of such multi-plex sections is not limited to the two sections illustrated but may comprise more than two sections.

Each multi-plex section is preferably spaced from the one above it to provide a chamber 41 for the entrance of leads to the electrodes from outside the electrode assemblage. A suitable spacer 49 of either conducting or insulating material may be positioned between the upper washer of one multiplex section and the lower washer of the multi-plex section above it. The outer grids II of all the sections may be made into an integral structure by constituting this grid of a single piece of sheet material. Suitable openings 5| through the spacer element and the outer grid at a level between the multi-plex sections will enable the electrode leads to be withdrawn in a comparatively simple manner.

In the lower portion of the device of Fig. 23, I have shown a third section. The outside housing is also a shield and it may and preferably is a continuation of outer grid IT. This outer grid may be of a solid sleeve or of mesh construction. Thetwo small cylinders 53 and 55 surrounding the cathode 1 may be called diode plates. As their name implies they are anodes by means of which diode rectification is provided. By having two such anodes, push-pull rectification can be accomplished.

As applied to a modern receiving set these two anodes may serve for push-pull rectification of the carrier in place of the customary second detector of a superheterodyne. In addition, the center tap of a transformer feeding these two anodes usually has a load resistance of high value. Across this load resistance, a direct current voltage, an audio frequency component, and a radio frequency component voltage appear.

The radio frequency component is usually not needed, and it may be by-passed to ground. The audio frequency component may be led by a proper impedance circuit to feed the audio frequency tubes. The direct current voltage can be coupled by means of proper impedance circuits to the grid returns of the various radio frequency and intermediate frequency tubes. Thus automatic volume control by means of these diode plates can be accomplished, by producing a bias for the proceeding tubes which varies directly as the strength of the carrier signal frequency.

The electrode and shielding arrangement of my invention enables one to construct tubes of unlimited number of designs. For example, in Fig. 24, I have disclosed a general form which such device may take. According to this modification, the device may be constructed in the form of a polygon of any number of sides 51 each side comp-rising one or more multi-plex sections of the types illustrated in Fig. 1, Fig. 18 and Fig. 23. As in the device of Fig. 23, a common cathode may be employed and leads to the electrodes may be withdrawn between multi-plex sections, and at the corners of the polygon. Should it be desired, a number of devices such as illustrated in Fig. 24 may be employed and in view of the fact that the shield ll of all of them may be maintained at the same potential, the devices may be mounted one on the other and their shields I! united in any manner desired.

Thus, it will be seen, that I have disclosed devices capable of fulfilling the objects of my invention. Various modifications and changes therein might occur to others skilled in the art without the exercise of invention. I therefore, do not desire to be limited in my protection to the specific details disclosed by me, except as may be required by the prior art and the appended claims.

I claim:

60 1. An electron discharge device comprising a cathode, a plurality of similar groups of electrodes disposed symmetrically about said cathode, each of said groups of electrodes comprising at least a control grid and an anode, elements of conductive material located intermediate said groups of electrodes and out of contact with the same, a grid element common to all of said groups and electrically connected to said conductive elements.

2. An electron discharge device comprising a cathode, a plurality of groups of electrodes disposed about said cathode, each of said groups comprising a pair of grid elements and an anode, theelectrodes of any one group being in spaced relationship to each other, a plurality of elements of conductive material disposed intermediate said groups of electrodes but spaced therefrom, at least one of said grids being electrically connected to said conductive elements.

3. An electron discharge device comprising a cathode, a plurality of groups of electrodes disposed with respect to said cathode, a plurality of conductive elements separating said groups of electrodes and an electrical connection between each of said conductive elements and one of the electrodes in its associated group, said connection being independent of said cathode.

4. An electron discharge device comprising a cathode, a plurality of groups of electrodes, disposed in operative position with respect to said cathode, conductive members between said groups of electrodes in spaced relationship thereto and electrostatically separating said groups,

-' and an electrical connection between said conductive members and at least one of the electrodes in each group, said connection being independent of said cathode.

5. An electron discharge device comprising a substantially evacuated housing, a cathode within said housing in line with the axis thereof, a plurality of groups of electrodes disposed in operative relationship to said cathode, each of said groups comprising at least a grid and an anode, a plurality of metallic terminalsmounted in the walls of said housing near its upper end, said terminals being disposed symmetrical to the axis of said device, and connections from said grids to said terminals.

6. An electron discharge device comprising a cathode, a plurality of conductive members disposed radially to said cathode, a plurality of groups of electrodes, each group being confined within the space defined by two of said radially disposed elements and comprising a control grid, an anode, a screen grid and a suppressor grid, and terminal connections to said electrodes and said conductive elements, said terminal connections extending external of said discharge device.

'7. An electron discharge device comprising a substantially evacuated housing having a base, a cathode within said housing in line with the axis thereof, a plurality of groups of electrodes disposed about said cathode, each group comprising a control grid, an anode, a screen grid and a suppressor grid, and terminal connections to said electrodes, said terminal connections extending external of said discharge device, certain of said connections comprising metallic caps mounted in the wall of said housing adjacent its upper end and disposed symmetrically about the axis thereof.

8. An electron discharge device comprising a substantially evacuated housing, a cathode within said housing in line with the axis thereof, a plurality of groups of electrodes disposed in operative relationship to said cathode, each of said groups comprising at least a grid and an anode, a plurality of metallic terminals mounted in the walls of said housing near its upper end, connections from electrodes of said groups to said terminals, said terminals and connections being so located as to reduce the capacity between said connections to a minimum.

'9. An electron discharge device comprising a cathode, at least one electrode disposed in cooperative relationship to said cathode but external thereto, a housing of conductive material disposed adjacent said cathode, and substantially enclosing said electrode, said housing having an opening therein facing said cathode, to permit of the free flow of electrons into said housing to said electrode.

10. An electron discharge device comprising a plurality of groups of electrodes, at least one of said groups being substantially enclosed in housings of conductive material having a wall facing outside of the device to shield said electrodes from electrical influences external of the device, and a cathode element common to all of said groups, and a portion of each of said housings being removed to permit of the flow of electrons into said housings to said groups of electrodes enclosed therein.

11. An electron discharge device comprising an envelope, a plurality of multi-plex sections therein, each multi-plex section comprising a plurality of groups of electrodes, and means for shielding said multi-pleX sections from each other and each group of electrodes from an adjacent group.

12. An electron discharge device comprising a cathode, within said device a plurality of electrical conductive members disposed radially to said cathode and out of electrical contact therewith, a plurality of anode electrodes, each anode being confined within the space defined by two of said radially disposed elements, and terminal connections to said electrodes and said conductive elements, said terminal connections extending external of said discharge device.

13. An electron device comprising a cathode and an anode, a housing for said anode comprising a pair of side walls of electrically conductive material and a top wall of conductive material, said top wall being supported by said side walls, an opening in said housing exposing said anode to said cathode and an envelope enclosing said cathode and said housing.

14. An electron discharge device comprising a plurality of conducting shielding compartments, a plurality of anode electrodes in one of said shielding compartments, a grid electrode and an anode electrode in another of said shielding compartments and means for supplying electrons to all of said anodes and said grid, said means being' in spacedrelationship to said shielding compartments. 7

15. An electron discharge device comprising an envelope, a plurality of electrode groups in said envelope, means for supplying electrons to said electrode groups, means for electrostatically shielding at least one of said groups from another group, said shielding means being out of electrical contact with said electron supplying means within said device, and means for .efiecting an external connection to said shielding means.

- MAXWELL K. GOLDS'I'EIN. 

